[1.6 FSI] Misfiring after warming up

[VETRA]

 

Hello everybody!

 

I am new to this forum and what brought me here is, as it often happens, a big problem that I can't figure out myself...

My lovely A2 1.6 FSI, which I own for less than a year started misfiring about 6 months ago. It started as barely noticeable and gradually it's getting worse and worse...

 

The engine works perfectly for 3-5 minutes after cold start.

Then after a little warming up (say, 3-5 km travelled): 

   Works ok at ide.

   Works ok (ish) at revs >4000 RPM.

   Noticeably misfires at RPMs around 2000-2500, especially around 50% throttle.

 

Check engine blinks then light up. Here are the errors I am getting all the time: 

 

Control Module Part Number: 036 906 013 F

Component and/or Version: MED7.5.11 4628

Software Coding: 00051

Work Shop Code: WSC 02138

Additional Info: WAUZZZ8Z53N005638 AUZ7Z0B2098087

VCID: 122DCA0A5E18EB8E3D9-5000

6 Faults Found:

 

17443 - Sensor for NOx (G295)

P1035 - 35-10 - Signal Implausible - Intermittent

16523 - Oxygen (Lambda) Sensor B1 S2

P0139 - 35-00 - Response too Slow

17584 - Bank1: O2 (Lambda) Correction Behind Catalyst

P1176 - 35-00 - Control Limit Reached

16684 - Random/Multiple Cylinder Misfire Detected

P0300 - 35-10 - - Intermittent

16685 - Cylinder 1

P0301 - 35-10 - Misfire Detected - Intermittent

16687 - Cylinder 3

P0303 - 35-10 - Misfire Detected - Intermittent

 

Misfiring cylinders are randomly different every time.

 

What I did so far:

Fuel system:

-          Replaced fuel filler cap – no effect

-          Replaced fuel filter – no effect

-          Replaced fuel pressure regulator – no effect

-          Replaced Activated charcoal canister – no effect

-          Replaced N80 solenoid valve – no effect

-          Used injector cleaning fuel additives several times – sometimes they seemed to have helped a little, maybe…

Ignition:

-          Replaced spark plugs – this probably helped a little

-          Replaced ignition coils – this helped a lot but didn’t solve the problem

Engine mechanics:

-          Checked compression
I did this in a garage – I don’t remember the numbers, but the guys said all cylinders are even and the values are good.

-          Cleaned up the grounding point behind the left headlight – didn’t do much.

 

Now I’m puzzled where to look next.

I attach also here a few logs.

Any advice will be highly appreciated! 

 

 

 

LOG-01-007-140-142.csv LOG-01-007-140-142 1.csv LOG-01-007-140-142 2.csv LOG-01-007-140-142 3.csv

[HellSoldier]

Hey Vetra,

 

just a few Tipps that i discoverd while having my 1.6FSI.

 

The Software from ProBoost did a LOT of a diffrence to the car. Highly recommended!

 

There are 2 diffrent Types of Misfires (at least in German).

 

One Type is caused by the Spartplugs and Coils. 

 

One is caused by coked injectors.

 

Since you have allready change the Plugs and Coils i would suggest to clean the Injectors.

 

Maybe try UMS -> https://ultimatesolutions.de/produkt/einspritzduesen-reinigung-service/#

 

I think they will help you out too, even when you are from France.

 

The Injectors have to be removed and send to them for cleaning and testing.

 

Good Luck!

 

greetz

Marius

 

[VETRA]

Thank you Marius!!

I spoke with my garage guys - they said they are quite afraid of the amount of labour for taking out the injectors... but it looks like this is the way to go...

(I live in a tiny village.........)

I'll study a bit - maybe I could try to do it myself...

 

Thanks again!

Cheers

Vitaly

[HellSoldier]

Hi Vitaly,

 

give it a try. Sadly the Injectors aren't available at the market anymore so you have to improvise :-D 

 

Let me know if it works!

 

Sometimes a Missfire can also be cause by some kind of leakage. Maybe its also worth a try to investigate this also.

 

cheers!

[lubomir]

Am 2.4.2025 um 18:29 schrieb VETRA:

Thank you Marius!!

I spoke with my garage guys - they said they are quite afraid of the amount of labour for taking out the injectors... but it looks like this is the way to go...

(I live in a tiny village.........)

I'll study a bit - maybe I could try to do it myself...

 

 

In this posting a guy describes, that he found an aftermarket alternative of new injectors and installed them.

https://a2-freun.de/forum/forums/topic/84861-16-fsi-einspritzdüsen-nicht-mehr-lieferbar/page/3/#findComment-1051310

He is very happy with them, but ther is no longtime-experience, because he just installed them.
I made a good experience with letting clean and refurbish www.vierliter.de a complete set of old injectors from ebay. Works perfect sinde 12.000 km. 

Problem is, that the correct injectors for an A2 are rare and therefore hard to find at an affordable price.

My garage needed 3,5 h to replace them, but they have A2 experience, so better calculate with 5-6h.

[VETRA]

On 4/3/2025 at 9:36 PM, HellSoldier said:

some kind of leakage

Thank you HellSoldier!

"Some kind of leakage" - you mean the air leak? Or coolant leak? Or fuel leak? 

My engine looks dry on the outside...  Any particular area to focus on?

Thanks again! 

[VETRA]

On 4/3/2025 at 11:21 PM, lubomir said:

In this posting a guy describes, that he found an aftermarket alternative of new injectors and installed them.

https://a2-freun.de/forum/forums/topic/84861-16-fsi-einspritzdüsen-nicht-mehr-lieferbar/page/3/#findComment-1051310

He is very happy with them, but ther is no longtime-experience, because he just installed them.
I made a good experience with letting clean and refurbish www.vierliter.de a complete set of old injectors from ebay. Works perfect sinde 12.000 km. 

Problem is, that the correct injectors for an A2 are rare and therefore hard to find at an affordable price.

My garage needed 3,5 h to replace them, but they have A2 experience, so better calculate with 5-6h.

Thank you Lubomir!

This is very interesting! 

I wrote the guy (Bastek555) a PM asking for more details...

Thanks again! 

[HellSoldier]

vor 18 Minuten schrieb VETRA:

Thank you HellSoldier!

"Some kind of leakage" - you mean the air leak? Or coolant leak? Or fuel leak? 

My engine looks dry on the outside...  Any particular area to focus on?

Thanks again! 

 

Hi, the Engines are kind of know for beeing extremly picky when it comes to air leaks and some big errors.

Check:

- Oil filling Tube (Front of the Engine, From the Serviceflap opening to the Oilpan) and the

- Crankcase Ventilation (Back of the Engine, only reachable from under the Car. Located under the Intake Manifold)

- EGR Tube (Driverside over the Gearbox to the Intakemanifold)
- Sealings of the Injectors (Inside of the Intakemanifold, really fuck*d up position)

Those bits are known for Airleaks and wrong Air/Fule ratios.

[VETRA]

Thanks HellSoldier! 

 

By the way, I sometimes have this error:

17443 - Sensor for NOx (G295)
P1035 - 35-10 - Signal Implausible - Intermittent

 

and most of the times this one:

P1033 - 35-10 - Signal Too Low - Permanent

 

Is this a cause of the misfires, or could this be the reason (impacting the fuel/air mixture to be too lean or too reach) ?

 

Is it worth taking out and cleaning the NOx sensor head? Or replacing the NOx sensor for a new one?

(they cost around 100Eur and they are not difficult to replace - as compared to the injectors...)

[HellSoldier]

I think it has nothing in common with the misfires.

 

It's definitly worth a try to replace it. For Petrol Engines its quite common that the Oxigensensors to fail over time.